The NCEDC archives several different earthquake catalogs:
- Northern California
The NCEDC currently hosts several different earthquake catalogs for Northern California.
The USGS produces a catalog based on data from the Northern California Seismic Network, which contains hypocenters and magnitudes, phase and amplitude readings, and first motion mechanisms. The NCSN catalog dates from 1967-present.
The BSL produces a catalog based on their networks, primarily the Berkeley Digital Seismic Network, which contains hypocenters and magnitudes, phase and amplitude readings, and seismic moment tensor solutions.
The USGS/NCSN and UCB/BDSN catalogs may be accessed through an online search interface
The USGS and BSL are working to create a unified or joint earthquake catalog which combines the observations from these agencies. This effort is underway, but progress is slow.
In addition to the UCB catalog of locations, magnitudes, and phase, a separate catalog of moment tensor solutions is available. At the present time, the moment tensor catalog is not available in a searchable structure, but a results file is accessible online
A third earthquake catalog is available for Northern California. The Townley-Allen catalog, is a compilation of earthquakes based on newspaper accounts, covers the period 1769-1927. It is not currently available in a searchable format, but a copy may be obtained from the NCEDC by anonymous ftp at
The NCEDC hosts the composite earthquake catalog generated by the Advanced National Seismic System (ANSS). The ANSS catalog contains information on earthquakes around the world. Earthquake information is contributed by the regional networks of the ANSS and by the USGS National Earthquake Information Center. More information about the ANSS composite catalog and search tools is available: